UK Accredited Structural Engineer Needed

I have recently had a first floor rear extension completed and the building regulator has requested the following:

• A copy of the structural engineers drawings and calculations are required, the engineer's
accreditation details should be on the head of each page.
• Clarification is required on the insulation build-up to the roof and walls, a confirmation of the achieved u-value is required.
• Confirmation required whether the roof is a warm or cold deck roof design.

I already have the drawings and calculations from a structural engineer I used but his accreditation details are missing.